1. Field of the Invention
The present invention relates to a semiconductor integrated circuit device and a redundancy method thereof. The invention is applied, for example, to an SRAM including a fuse box.
2. Description of the Related Art
Conventionally, there is known a semiconductor integrated circuit device wherein a blow-type fuse element, such as an eFuse, is used, and an electric current is caused to flow in the fuse element, thereby blowing the fuse element and programming data (see, e.g. Jpn. Pat. Appln. KOKAI Publication No. H9-7385 and Jpn. Pat. Appln. KOKAI Publication No. 2001-118996). For example, by blowing a fuse element, the resistance value of the programmed fuse element is more increased by an order of magnitude than the resistance value of the fuse element before programming.
In the case of using the blow-type fuse element, however, if program is once executed, the fuse element is broken, and rewrite of the associated bit is disabled. In a case where rewrite is necessary, a fuse element of a different bit is additionally prepared, and it is necessary to execute write in this different fuse element.